AJP - Regulatory, Integrative and Comparative Physiology, Vol 270, Issue 1 94-R98, Copyright © 1996 by American Physiological Society
Vasopressin responses to corticotropin-releasing factor and hypertonicity after truncal vagotomy in dogs
H. Raff, P. E. Papanek and V. E. Cowles
Department of Physiology, Medical College of Wisconsin, Milwaukee, USA.
Infusion of corticotropin-releasing factor (CRF) augments the plasma
vasopressin response to infusion of hypertonic saline in conscious dogs.
Furthermore, afferent vagal nerve input from the abdomen is involved in the
control of vasopressin release and may be altered by CRF. The purpose of
the present study was to characterize the effect of CRF on the vasopressin
response to hypertonic saline and to determine if it is mediated by
afferent input carried from the abdominal vagus. Conscious male dogs (n =
5) underwent infusion of isotonic saline (vehicle), CRF (10 or 20
ng.kg-1.min-1), hypertonic saline (0.2 mmol.kg-1.min-1), or the combination
of CRF and hypertonic saline. Hypertonic saline increased plasma sodium
from 147 +/- 1 to 153 +/- 1 meq/1 and plasma vasopressin from 2.5 +/- 0.1
to 5.8 +/- 0.4 pg/ml. CRF infusion alone had no effect on plasma
vasopressin. The addition of 10 or 20 ng.kg-1.min-1 CRF augmented the
vasopressin response to hypertonic saline to 7.7 +/- 1.7 and 6.9 +/- 0.3
pg/ml, respectively. Truncal vagotomy did not attenuate the vasopressin
response to hypertonic saline with or without CRF infusion. We conclude
that CRF augments the vasopressin response to hypertonic saline and that
this effect is not mediated via afferents from the abdominal vagus.
